Kubernetes, originally announced back in June, is a management tool for handling Docker containers. It can automatically deploy the containers across a cluster in a load-balanced way.

Originally devised for Docker management in Google's back end, it's since been released as an open source project. The list of contributors who have just signed on to add their own code reads like a who's who of cloud and platform giants: Microsoft, Red Hat, IBM, CoreOS, SaltStack, and Mesosphere.

Some of the contributions seem obvious. SaltStack, for instance, is adding Kubernetes as part of its own automation framework. But the presence of other contributors has subtler implications.

As for Red Hat itself, its plans for Kubernetes revolve around the so-called open hybrid cloud. The implication is that Kubernetes will become a part of its ongoing integration efforts between Red Hat Enterprise Linux and OpenStack. One way that could be implemented is with Docker containers being used to move applications and their attendant workloads between public and private clouds.

Microsoft's plan for Kubernetes is plain enough, based on its own words: To allow it to work well in Azure-hosted Linux environments. But given that Microsoft might also be working to bring Docker to Windows in some form, investing in Kubernetes as a run-up to that makes sense.

Creations like Kubernetes don't just point at how Docker has become a software ecosystem unto itself, although that's become plain from the sheer amount of activity around (and inside) the project and the number of third-party services building on top of it. It's also a sign of how third parties are preparing to make a long-term commitment to that ecosystem and in multiple environments.